Question: $ { {-4} \times \left[\begin{array}{rrr}{1} & {4} & {2} \\ {0} & {2} & {0}\end{array}\right] = {?} } $
Explanation: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-4}\times{1} & {-4}\times{4} & {-4}\times{2} \\ {-4}\times{0} & {-4}\times{2} & {-4}\times{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-4} & {-16} & {-8} \\ {0} & {-8} & {0}\end{array}\right]}$